Treatment of cellulose acetate materials



Patented Dec. 12, 1933 1,939,:61 TREATMENT or CELLULOSE .ws'rs'ra'm'rsamas Archibald John Hall, 'limbersbrook, England,

.assignor .to Celanese Corporation of America,

a corporation of Delaware No Drawing. Original application July 22,1925, Serial No. 45,416, and in Great Britain July 31, 1924. Divided andthis application December 24, 1929. Serial No. 416,804

Claims.

It is well known that when cellulose acetate artificial silk is immersedin boiling water or water whose temperature exceeds about 85 0.,

it becomes curly or woolly, and loses a considerable proportion of itslustre and transparency. I

0 have now discovered and this discovery forms the basis of thisinvention, that the resistance against loss of transparency and lustreof such silk when heated at about 100 C..'for prolonged periods in thepresence 01' water, is increased by the presence of soluble salts ofmultl-valent metals.

The following salts are examples of suitable protective agents forcellulose acetate artificial silk:Magnesium nitrate, magnesium chloride,magnesium sulphate, calcium chloride, barium chloride, strontiumchloride, zinc chloride, zinc sulphate, cadmium chloride, coppersulphate, alum, chrome alum, iron alum, ferrous sulphate, ferrousammonium sulphate, aluminium chloride.

All the above substances exert their protective action for celluloseacetate when used in from 10% to queous solution, but it is to beunderstood that these concentrations are only stated by way oi exampleand that it is not to be inferred that all solutions of concentrationsfalling outside these limits are unsuitable for protecting celluloseacetate artificial silk against delustrlng.

In the use of soluble salts of multivalent metals as protective agentsin the treatment.ofcellulose acetate artificial silk with hot aqueousliquors. the presence in such liquors of substances-likely toprecipitate the metals, for example common soaps, should be avoided.

Among numerous p covery has useful applications are: the dyeing inboiling liquors of fabrics containing cellulose acetate and woollenfibres, the of dyed cellulose acetate fabrics in boiling liquors and therelief or production of latent strains in cellu-p lose acetate fabricsorproducts by. immersion in a boiling aqueous liquor.

whatlclaimanddesiretosecurebyletters Patent is:

LProcess for-preventing loss of lustre in bleaching. dyeing. printing,steaming and otherinwhichmydis-' wise treating textile materials, filmsand other materials comprising cellulose acetate at temperatures inexcess of about 85 0., characterized in that the treatment is eiiectedin presence of a soluble salt of amultivalent metal of a valency up toand including three, in aqueous solution of a concentration of at least10%.

2. Process for preventing loss of lustre inbleaching, dyeing and otheraqueous treatments of textile materials, films and other materialscomprising cellulose acetate at temperatures in excess of about 85 (3.,characterized in that the treatment is effected in presence of a solublesalt of a divalent metal, in aqueous solution of a concentration of atleast 10%.

3. Process for preventing loss of lustre in bleaching, dyeing and otheraqueous treatments of textile materials, films and other materialscomprising cellulose acetate at temperatures in excess of about 85 0.,characterized in that the, treatment is eifected in presence of asoluble salt of a multivalent metal, of a valency up to and includingthree, in aqueous solution of 10 to 30% concentration.

4. Process for preventing loss of lustre in bleaching, dyeing and otheraqueous treatments of textile materials, films and other materialscomprising cellulose acetate at temperatures in excess of about 85 0.,characterized in that the treatment is eflfected in presence of asoluble salt of a divalent metal, in aqueous solution of 10 to 30%concentration.

5. Process for preventing loss of lustre, in I salt of a multivalentmetal of a valency up to and including three in aqueous solution of aconcentration of at least 10%. v

. ARCHIBALD JOHN HALL.

